The genus Pseudomonas comprises a diverse group of bacteria that are involved in the pathogenicity of plants and animals including humans, in the biotransformation of natural and synthetic wastes including highly toxic hazardous compounds and in the development of new industrial products such as surfactants, polysaccharides, various organic acids, enzymes, vitamins, amino acids, antibiotics and a host of other compounds. lt is, therefore, no accident that the first two genetically altered strains that have been proposed to be released into the environment for protection of plants from frost-related damage or the attack by insect pests are pseudomonas viz. P. syringae and P. fluorescens. Although intense work in various aspects of Pseudomonas biology has been going on in both the United States and elsewhere in the world, the last major meeting on Pseudomonas held in the United States was more than a decade ago---an ASM sponsored symposium in 1976 in Orlando, Florida. The proposed meeting in Chicago during July 9-13, 1989 is therefore long overdue and is expected to attract more than 400 participants from the international scientific community.